--- a/slides01.tex	Wed Sep 26 02:08:55 2012 +0100
+++ b/slides01.tex	Wed Sep 26 02:50:44 2012 +0100
@@ -228,16 +228,50 @@
 \end{frame}}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\mode<presentation>{
+\begin{frame}[c]
+\frametitle{\begin{tabular}{c}A Web Crawler\end{tabular}}
+
+\begin{enumerate}
+\item given an URL, read the corresponding webpage
+\item extract all links from it
+\item call the web-crawler again for all these links
+\end{enumerate}
+
+\end{frame}}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+\mode<presentation>{
+\begin{frame}[c]
+\frametitle{\begin{tabular}{c}A Web Crawler\end{tabular}}
+
+\begin{enumerate}
+\item given an URL, read the corresponding webpage
+\item if not possible print, out a problem
+\item if possible, extract all links from it
+\item call the web-crawler again for all these links
+\end{enumerate}\bigskip\pause
+
+\small (we need to bound the number of recursive calls)
+
+\small (the purpose is to check all links on my own webpage)
+\end{frame}}
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 \mode<presentation>{
 \begin{frame}[c]
 \frametitle{\begin{tabular}{c}Scala\end{tabular}}
 
-\footnotesize a simple function for reading webpages
+\footnotesize a simple Scala function for reading webpages\\[-3mm]
 
 {\lstset{language=Scala}\fontsize{8}{10}\selectfont
 \texttt{\lstinputlisting{app0.scala}}}\pause\bigskip
 
+\footnotesize slightly more complicated for handling errors:\\[-3mm]
+
 \footnotesize
 {\lstset{language=Scala}\fontsize{8}{10}\selectfont
 \texttt{\lstinputlisting{app1.scala}}}